I'm finishing my basement and used the technique from This Old House to insulate and build the wood structure of the walls.

It involves attached 2in foam board insulation to the foundation walls along with horizontal and then vertical strapping on top of the horz. I've learned that code wants wires to be 1.5 inches from the front plane where the drywall will be attached. Each strapping is 1in thick, so when the wire is traveling horz. it's probably greater than 1.5 inch away, but when it travels vertically, in needs to travel over the horizontal strapping meaning it's < 1in away. How do I handle this?


  • 1
    It is actually 1-1/4” from the face of the wood for a bored hole or to the side of a furring strip. See exhibit 300.2 in the 2017 NEC code book for an example.
    – Ed Beal
    Feb 10, 2020 at 23:25

1 Answer 1


That's only really true where wiring passes through studs (and fastener penetration is likely). Because no one should be mounting anything to those recessed straps, I doubt it's a concern. I'd run the vertical wires in the middle of the stud space and move on. The obvious alternative is to use EMT (metal pipe).

Here's a discussion that seems to address this exact issue (though the images are broken, unfortunately). The consensus seems to be that there are no setback rules except where wires pass through the studs.

To be sure you'll pass inspection, ask your inspector.

  • The images work if you copy the image URL and paste it into a new tab. That looks like some trickery that photobucket uses to stop/annoy people from deep linking.
    – JPhi1618
    Feb 10, 2020 at 22:19
  • Yeah, photobucket wants you to pay extra to embed photobucket-hosted photos in third-party pages. I'm unclear on whether the photo publisher needs to pay, or the viewer does. Feb 11, 2020 at 2:53

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